An aerosol is a suspension of fine solid particles or liquid droplets in air or another gas.[1] Aerosols can be natural or anthropogenic. Examples of natural aerosols are fog or mist, dust, forest exudates and geyser steam. Examples of anthropogenic aerosols are particulate air pollutants and smoke.[1] The liquid or solid particles have diameters typically less than 1 μm; larger particles with a significant settling speed make the mixture a suspension, but the distinction is not clear-cut. In general conversation, aerosol usually refers to an aerosol spray that delivers a consumer product from a can or similar container. Other technological applications of aerosols include dispersal of pesticides, medical treatment of respiratory illnesses, and combustion technology.[2] Diseases can also spread by means of SMALL droplets in the breath, also called aerosols (or sometimes bioaerosols).[3] Aerosol science covers GENERATION and removal of aerosols, technological application of aerosols, effects of aerosols on the environment and people, and other topics.[1] Contents 1 Definitions 2 Size distribution 3 Physics 3.1 Terminal velocity of a particle in a fluid 3.2 Aerodynamic diameter 3.3 Dynamics 3.3.1 Coagulation 3.3.2 Dynamics regimes 3.3.3 Partitioning 3.3.4 Activation 3.3.5 Solution to the general dynamic equation 4 Generation and applications 5 Stability of generated aerosol particles 6 Detection 6.1 In situ observations 6.2 Remote sensing approach 6.3 Size selective sampling 7 Atmospheric 7.1 Effects 8 See also 9 References 10 Works CITED 11 Further reading 12 External links Definitions Fly ASH particles shown at 2,000 times magnification Photomicrograph made with a Scanning Electron Microscope (SEM): Fly ash particles at 2,000× magnification. Most of the particles in this aerosol are nearly spherical. Aerosol is defined as a suspension system of solid or liquid particles in a gas. An aerosol includes both the particles and the suspending gas, which is usually air.[1] Frederick G. Donnan presumably first used the term aerosol during World War I to describe an aero-solution, clouds of microscopic particles in air. This term developed analogously to the term hydrosol, a colloid system with water as the dispersed medium.[4] Primary aerosols contain particles introduced directly into the gas; secondary aerosols FORM through gas-to-particle conversion.Explanation: